// Copyright © 2019 The Things Network Foundation, The Things Industries B.V.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

/**
 * Extracts the value of a cookie if it exists.
 *
 * @param {string} key - The key of the entry to extract.
 * @returns {string} The extracted value.
 */
export default key => {
  const matches = document.cookie.match(
    new RegExp(`(?:^|; )${key.replace(/([.$?*|{}()[\]\\/+^])/g, '\\$1')}=([^;]*)`),
  )

  return matches ? decodeURIComponent(matches[1]) : undefined
}
